Changing apparatuses of the kind recited above are used in microscopes as retainers for selectable attachment of optical elements, e.g. fluorescence filter blocks. Reference is made in this connection, by way of example, to DE 199 36 497 A1, which discloses a changing apparatus in which the optical elements to be mounted on a carrying body are each equipped with a dovetail slide that is installed on an abutting surface of the carrying body. Attached in front of the abutting surface, as interacting retainer components, are a peg-shaped bolt and, next to the latter, a compression spring bent away under tension by the bolt. As a result of the tension of the bent compression spring, the latter and the bolt are pressed onto the inner sides of the dovetail slide pushed against the abutting surface.
This previously known changing apparatus is disadvantageous in that the respective optical element, with its dovetail slide, must be clamped onto the spring structure, constituted from the bolt and the compression spring, from the side, i.e. in a direction that is substantially parallel to the abutting surface of the carrying body. For this reason the carrying body must be immobilized, for example by means of a brake provided expressly therefor, in order for the optical elements to be coupled on, so as to prevent an undesired rotary motion of the carrying body that complicates installation. In addition, with the spring structure recited above, the deflection of the compression spring must be precisely adjusted in order to achieve the desired clamping effect in the installed state.
From documents DE 199 24 686 A1 and US 2008/0043324 A1 changing apparatuses are known which respectively include a carrying body, supported rotatably around a rotation axis. An optical element can be releasably mounted on the carrying body.